The invention relates to a method and a device for the efficient transmission of program and service data for national and regional broadcast.
In geographically large countries such as the USA, national programs for a nationwide broadcast and regional programs for a regional broadcast are combined simultaneously in a single transport stream of a digital television transmission.
As shown in FIG. 1, TV program and service data determined for regional and national broadcast have conventionally been generated centrally or de-centrally as individual MPEG2 transport streams, supplied to the central headend (distribution head) in each case via a data link, and each combined within the central headend into one transport stream for each region. Accordingly, for example, for digital TV transmission in the USA, under the Advanced Television Systems Committee Standard (ATSC Standard), the identical national program content for all regions is combined in each case in an ATSC multiplexer with the respectively different regional program content for each region to form a transport stream broadcast in the respective region. The transport streams associated with the individual regions are typically transmitted from the central headend via one or more satellite-supported STL data link to the individual, regionally distributed transmitters.
The data transmission from the central headend to the individual transmitters demands an unnecessarily large transmission bandwidth, since the program and service data determined for national broadcast are transmitted from the central headend to the individual transmitters several times corresponding to the number of transport streams. Moreover, program and service data determined for mobile receivers are unnecessarily already coded in the central headend, although a complex coding implemented additionally for program and service data to mobile receivers is required only on the transmission path from the regional transmitters to the mobile receivers. This represents a waste of necessary transmission data rate in an ATSC-M/H Advanced-Television Systems Committee-Mobile/Handheld) transmission system for mobile and stationary receivers by comparison with an ATSC transmission system for stationary receivers, in which a coding of this kind has not hitherto been implemented. In the least favourable case, 83.1% of the required transmission data rate for coding is wasted in this context.
Regarding the prior art, reference is made to DE 199 60 295 A1. It is known from DE 199 60 295 A1 that marked data packets can be extracted from the datastream for different regional programs through their PID.